1. Field
One or more embodiments of the present invention relate to a battery unit and a battery module using a plurality of battery units coupled with each other.
2. Description of the Related Art
In general, secondary batteries can be discharged and recharged repeatedly, unlike primary batteries that are not designed to be recharged. Secondary batteries are used as energy sources for mobile devices, electric vehicles, hybrid cars, electric bikes, uninterruptible power supplies, etc. Also, secondary batteries are used in the form of a single battery or in the form of a battery module in which a plurality of batteries are electrically coupled in a single unit by using a bus bar, the form being in accordance with the type of an external device adopting the secondary battery.
A compact mobile device, such as a mobile phone, with the output and capacity of a single battery may operate for a predetermined time. However, when an operation of longer duration or higher power is needed, as in electric vehicles or hybrid cars, a battery module is often used to reduce or prevent an output or capacity problem. The battery module may increase an output voltage or an output current according to the number of batteries included in the battery module. The battery module may reach a desired output voltage or output current by coupling a plurality of batteries in series or in parallel.